When playing a guitar, it is often desirable to change the natural or unfretted key of the guitar strings in order to produce a sound of higher or lower frequency as the strings are plucked or strummed. This is normally accomplished by the act of "fretting" the strings against the neck of the guitar. The guitar neck is usually provided with a series of thin metal strips extending perpendicular to the axis of the neck, against which the strings may be forced, either individually or as a group. This action is known as "fretting." The action changes the effective length of the strings so that vibration of each string will result in a sound of a predetermined frequency, different from every other sound which will be generated when the string is forced against any other fret.
In the past, many guitar players have produced such fretting by employing a device known as a "capo." In general, such capos generally comprise a barr which can be pressed against the strings of the guitar at a selected position along the length of the neck. The barr is usually held in place by an elastic band or other tying device which prevents movement of the barr relative to the neck. When the capo is mounted on the neck of the guitar, it presses the strings against the next lower fret so that each time one of the strings is plucked, it will produce a sound of predetermined frequency depending upon the fret selected, unless it is also individually fretted at a lower position by a finger of the player. In other words, a capo will effectively change the tuning of the guitar without requiring that each string be individually retuned.
When certain musical selections are played, however, it is sometimes desirable to fret all of the strings at a predetermined position only temporarily and to relieve that fretting after a selected number of notes or chords have been played. In such cases, it has become common for players to utilize the index finger of the hand which controls the fretting of the strings to accomplish a fretting of all the strings at a predetermined position. While this is accomplished, the remaining three fingers of the hand may be used to individually fret up to three of the strings at lower positions.
Unfortunately, not all players find it comfortable or convenient to accomplish such index finger fretting. Many have difficulty arranging their hands and arms in such a way that their index fingers can be properly positioned to accomplish the fretting, while allowing their remaining three fingers to curve sufficiently to achieve independent string fretting without touching any of the other strings and reducing the quality of the sound of such other strings. Further, many players find it undesirable to fret all of the strings with their index finger, preferring to use four fingers instead to fret individual strings. Accordingly, it has become desirable to provide a device which will allow the player to achieve the versatility of both index finger fretting and the sounds which can be achieved utilizing a capo.